Medical Imaging Dataset Validation Report
Date: November 23, 2025
Validation Tool Version: 1.0
Base Directory: /Users/dafesmith/Documents/repo/NeMo-agent/medical_ehr/data/imaging/
Executive Summary
| Metric | Value |
|---|---|
| Total Datasets | 4 |
| Total Files | 633 |
| Valid Files | 620 |
| Invalid Files | 13 |
| Total Size | 385.38 MB |
| Validation Rate | 97.95% |
Datasets Downloaded
1. Chest X-ray (Pneumonia Detection)
| Property | Value |
|---|---|
| Source | HuggingFace: hf-vision/chest-xray-pneumonia |
| Location | chest_xray/pneumonia/ |
| Total Files | 203 |
| Valid Files | 203 (100%) |
| Total Size | 313.03 MB |
| Image Format | PNG |
| Image Resolution | Variable (avg ~1500x1200 pixels) |
File Types:
- PNG images: 200
- JSON metadata: 2
- CSV labels: 1
Label Distribution:
- Label 0 (Normal): 200 images
Sample Files:
0_00124.png(1430x1128, 1.2 MB)0_00130.png(1654x1368, 1.8 MB)0_00118.png(1828x1511, 1.9 MB)
2. Brain MRI (Alzheimer Detection)
| Property | Value |
|---|---|
| Source | HuggingFace: Falah/Alzheimer_MRI |
| Location | brain_mri/alzheimer/ |
| Total Files | 203 |
| Valid Files | 203 (100%) |
| Total Size | 2.97 MB |
| Image Format | PNG |
| Image Resolution | 128x128 pixels |
File Types:
- PNG images: 200
- JSON metadata: 2
- CSV labels: 1
Label Distribution:
- Label 0 (Mild Demented): 29 images
- Label 1 (Moderate Demented): 2 images
- Label 2 (Non Demented): 102 images
- Label 3 (Very Mild Demented): 67 images
Sample Files:
2_00007.png(128x128, 14.7 KB)0_00118.png(128x128, 14.7 KB)3_00070.png(128x128, 16.6 KB)
3. Dermatology (Skin Cancer Classification)
| Property | Value |
|---|---|
| Source | HuggingFace: marmal88/skin_cancer |
| Location | dermatology/skin_cancer/ |
| Total Files | 203 |
| Valid Files | 203 (100%) |
| Total Size | 68.77 MB |
| Image Format | PNG |
| Image Resolution | 600x450 pixels |
File Types:
- PNG images: 200
- JSON metadata: 2
- CSV labels: 1
Label Distribution:
- Actinic Keratoses: 200 images
Additional Metadata Fields:
- image_id, lesion_id, dx_type, age, sex, localization
Sample Files:
actinic_keratoses_00056.png(600x450, 310 KB)actinic_keratoses_00042.png(600x450, 392 KB)actinic_keratoses_00095.png(600x450, 383 KB)
4. DICOM Samples (Multi-modality Test Files)
| Property | Value |
|---|---|
| Source | PyDICOM GitHub Repository |
| Location | dicom_samples/ |
| Total Files | 24 |
| Valid Files | 11 (45.8%) |
| Invalid Files | 13 |
| Total Size | 0.60 MB |
| Format | DICOM (.dcm) |
File Types:
- DICOM files: 23
- JSON metadata: 1
Successfully Validated DICOM Files:
| Filename | Modality | Study Date | Size |
|---|---|---|---|
| MR_small.dcm | MR | 20040826 | 9.6 KB |
| MR_small_bigendian.dcm | MR | 20040826 | 9.7 KB |
| MR_small_implicit.dcm | MR | 20040826 | 9.7 KB |
| MR_small_RLE.dcm | MR | 20040826 | 7.8 KB |
| MR_small_expb.dcm | MR | 20040826 | 9.8 KB |
| CT_small.dcm | CT | - | 39.7 KB |
| ExplVR_BigEnd.dcm | - | - | 15.4 KB |
| VR-2022.dcm | - | - | 258 KB |
| J2K_pixelrep_mismatch.dcm | - | - | 138.5 KB |
Files with Validation Issues (codec/format issues, not corruption):
- JPEG Extended transfer syntax (requires specific codecs)
- JPEG-LS files (requires pyjpegls or GDCM)
- Files without DICM header (legacy format)
- JPEG2000 with bit depth issues
Directory Structure
/Users/dafesmith/Documents/repo/NeMo-agent/medical_ehr/data/imaging/
βββ brain_mri/
β βββ alzheimer/
β βββ images/ (200 PNG files)
β βββ metadata/ (labels.csv, labels.json, summary.json)
βββ chest_xray/
β βββ images/ (empty - not used)
β βββ metadata/ (empty - not used)
β βββ pneumonia/
β βββ images/ (200 PNG files)
β βββ metadata/ (labels.csv, labels.json, summary.json)
βββ ct_scans/
β βββ lidc_idri/ (empty - requires TCIA download)
βββ dermatology/
β βββ skin_cancer/
β βββ images/ (200 PNG files)
β βββ metadata/ (labels.csv, labels.json, summary.json)
βββ dicom_samples/
β βββ brainix/ (empty - requires premium access)
β βββ manix/ (empty - requires premium access)
β βββ *.dcm (23 DICOM test files)
βββ medical_docs/
β βββ ocr_samples/ (empty - future use)
βββ download_medical_imaging.py
βββ download_chest_xray.py
βββ validate_datasets.py
βββ download_summary.json
βββ validation_results.json
βββ validation_report.md (this file)
Issues Encountered
1. HuggingFace Dataset Script Deprecation
Issue: The original alkzar90/NIH-Chest-X-ray-dataset uses deprecated dataset scripts.
Error: RuntimeError: Dataset scripts are no longer supported
Resolution: Used alternative dataset hf-vision/chest-xray-pneumonia with modern Parquet format.
2. OsiriX DICOM Library Access
Issue: OsiriX sample datasets (BRAINIX, MANIX) require premium membership.
Resolution: Downloaded alternative DICOM test files from PyDICOM GitHub repository.
3. DICOM Codec Dependencies
Issue: Some DICOM files require specialized codecs (JPEG-LS, GDCM) for pixel data extraction.
Error Types:
- "JPEG Extended only supported by Pillow if Bits Allocated = 8"
- "Missing required dependencies: GDCM, pyjpegls"
Resolution: Files are valid DICOM, but pixel data extraction requires additional libraries. For testing purposes, the available files with standard transfer syntaxes are sufficient.
4. Kaggle CLI Not Available
Issue: Kaggle CLI not installed, preventing direct NIH Chest X-ray dataset download.
Resolution: Used HuggingFace as primary source.
Validation Details
Image Validation Checks
- File Integrity: PIL Image.verify() for PNG/JPG files
- Format Verification: Confirmed PNG format and RGB mode
- Size Measurement: File size and image dimensions
- Metadata Presence: Checked for labels.csv and labels.json
DICOM Validation Checks
- DICM Magic Number: Checked for DICOM preamble
- Metadata Extraction: Patient ID (anonymized), Modality, Study Date
- Pixel Data: Attempted pixel array extraction where possible
Recommendations
Immediate Next Steps
Install DICOM Codecs (optional):
pip install pylibjpeg pylibjpeg-libjpeg pyjpeglsDownload More Chest X-rays: Current sample has limited label diversity (all label 0). Consider downloading balanced dataset.
Add CT Scan Data: LIDC-IDRI requires TCIA Data Retriever. Alternative: use Stanford AIMI datasets.
For Production Use
- PhysioNet Credentialing: Register for MIMIC-CXR access (224,316 chest X-rays)
- TCIA Registration: Access LIDC-IDRI (1,018 CT scans with annotations)
- VinDr-CXR: Consider Vietnamese chest X-ray dataset (18,000 images)
Data Augmentation
Consider augmenting the current datasets:
- Random rotations, flips, brightness adjustments for training
- Resize consistency (all images to standard size like 224x224)
Files Created
| File | Purpose | Size |
|---|---|---|
download_medical_imaging.py |
Main download script | 6 KB |
download_chest_xray.py |
ChestX-ray14 download (legacy) | 3 KB |
validate_datasets.py |
Validation script | 6 KB |
download_summary.json |
Download metadata | 1 KB |
validation_results.json |
Detailed validation output | 11 KB |
validation_report.md |
This report | 8 KB |
Appendix: Dataset Sources
| Dataset | Source | License | Registration Required |
|---|---|---|---|
| Chest X-ray Pneumonia | HuggingFace | CC0 | No |
| Alzheimer MRI | HuggingFace | Unknown | No |
| Skin Cancer | HuggingFace | CC BY-NC-SA 4.0 | No |
| DICOM Samples | PyDICOM | MIT | No |
| LIDC-IDRI | TCIA | CC BY 3.0 | Yes (TCIA) |
| MIMIC-CXR | PhysioNet | PhysioNet | Yes (PhysioNet) |
| OsiriX Samples | OsiriX | Premium | Yes (Paid) |
Report Generated: 2025-11-23T13:37:06 Validation Script: validate_datasets.py Download Script: download_medical_imaging.py